An integrated gasification combined cycle (IGCC) has conventionally been developed and put into practical use in order to improve power generation efficiency in a coal-fired power plant, for example.
The integrated gasification combined cycle has advantages in that it uses coal resources with abundant reserves, an air pollutant such as carbon dioxide is emitted less since the thermal efficiency is higher than that of the conventional pulverized coal-fired power generation, and ashes of coal is discharged as vitreous molten slag to have a smaller volume. Accordingly, the development of an integrated gasification combined facility is in progress as a leading technology of the future coal-fired power generation.
The integrated gasification combined cycle here includes: a gas turbine which operates with a fuel that is a coal gas obtained by gasifying coal; and a steam turbine which operates with steam obtained by recovering exhausted heat from the gas turbine (Patent Literature 1).
In recent years, the development of the integrated gasification combined cycle using a pressurized coal gasification furnace is in progress in order to improve power generation efficiency at a coal-fired power plant (Patent Literature 2).
Unlike a conventional combustion boiler, the pressurized coal gasification furnace has a gasification furnace and a gas cooler that are provided in a pressure vessel, the pressure in which is set to 3 MPa, for example.